WEST BOUNTIFUL — Holly and Flying J refineries lost power for about two hours Friday night, resulting in plumes of smoke and flames filling the air and causing residents concern.

The fire and smoke were part of the refineries’ safety measures in place in case they lose power, said Holly/Frontier spokesman Mike Astin.

In the process, gases were emitted to keep pressure from building. The smoke and flame continued for about an hour until the pressure began to drop, Astin said. Power was out at the two refineries for about two hours.

The power outage occurred because of blown fuses at Rocky Mountain Power’s Woods Cross substation about 6 p.m.

The disturbance also affected Chevron and Silver Eagle, although power did not go out at those refineries.